Method and system for layerwise forming an object from a medium capable of solidification

Abstract

An additive manufacturing method and system for layerwise forming an object from a medium capable of solidification, wherein successive layers of the medium are applied using a nozzle head including a plurality of discrete nozzles being spaced apart from each other, each nozzle having an opening area through which a continuous stream of the medium is dischargeable for impinging a coverage area on a layer of the medium on a support and/or an already formed part of the object. The continuous streams are non-intersecting. The nozzle head and the support are relatively movable with respect to each other in at least one running direction.

The invention claimed is: 
     
         1 . A method for layerwise forming an object from a medium capable of solidification, whereby the object is built up layer per layer by:
 repeatedly, evenly, and uniformly providing a recoating layer of the medium on a support and/or an already formed part of the object and by subsequently selectively solidifying one or more selected areas of the recoating layer of the medium according to a specific pattern before a successive recoating layer is formed in a same manner;   wherein the successive recoating layer of the medium is applied using a recoater comprising a nozzle head which further comprises a plurality of nozzles spaced apart from each other,   wherein each nozzle has an opening area through which, during application of the successive recoating layer, a continuous stream of the medium is discharged downwards, in a stable jet lacking droplet breakup, for impinging a coverage area on the recoating layer of the medium on the support and/or the already formed part of the object,   wherein the plurality of nozzles are arranged to provide a corresponding plurality of continuous streams,   wherein individual ones of the plurality of continuous streams are non-intersecting,   wherein each continuous stream, of the plurality of continuous streams, maintains coherence with an unbroken and intact outer boundary remaining without segmentation into droplets at least until contacting a surface of the recoating layer,   wherein the nozzle head and the support are relatively movable with respect to each other in at least one running direction, and   wherein, in one or more runs of the nozzle head in the at least one running direction, the coverage areas of the continuous streams cover an entire coverage width defined as a total span across which the continuous streams are applied in the at least one running direction.   
     
     
         2 . The method according to  claim 1 , wherein the coverage areas of the continuous streams cover the entire coverage width in a single run. 
     
     
         3 . The method according to  claim 1 , wherein the coverage areas of the continuous streams in the at least one running direction discharged from the plurality of the nozzles form deposition paths, wherein the deposition paths at least partially overlap. 
     
     
         4 . The method according to  claim 1 , wherein the nozzle head comprises a plurality of nozzle arrays, including at least a first nozzle array and a second nozzle array,
 wherein each nozzle array, of the first nozzle array and the second nozzle array, comprises a series of nozzles configured to emit continuous streams;   wherein nozzles of the first nozzle array positionally offset relative to nozzles of the second nozzle array such that coverage areas of the continuous streams of the nozzles in the first array at least partially overlap coverage areas of the continuous streams of the nozzles in the second array during one or more runs of the nozzle head in the at least one running direction.   
     
     
         5 . The method according to  claim 4 , wherein in the at least one running direction the opening areas of the nozzles of the first array at least partially overlap with respect to the opening areas of the nozzles of the second array. 
     
     
         6 . The method according to  claim 4 , wherein neighboring coverage areas in a same coverage area array are distanced at a coverage area pitch measured from a center point of the coverage area to a center point of the neighboring coverage area in the same coverage area array. 
     
     
         7 . The method according to  claim 4 , wherein the coverage areas of successive arrays are offset at a coverage area array pitch in the at least one running direction,
 wherein the coverage area array pitch is measured from a first line going through center points of the coverage areas of the first array to a second line going through center points of coverage areas of the second array, and   wherein the coverage area array pitch is larger than two times a coverage area diameter.   
     
     
         8 . The method according to  claim 1 , wherein a single successive recoating layer is provided by performing a plurality of runs in the at least one running direction,
 wherein, in a first run, paths of the coverage areas of the continuous streams discharged from the plurality of nozzles in the at least one running direction are distanced from each other with non-covered regions therebetween,   wherein the non-covered regions are subsequently covered by performing one or more additional runs,   wherein, prior to performing the one or more additional runs, the coverage areas are shifted in a direction transverse to the running direction such that the paths of the coverage areas during the additional run cover at least a portion of the non-covered regions.   
     
     
         9 . The method according to  claim 1 , wherein nozzles are arranged to selectively dispense a continuous stream of the medium,
 wherein the nozzles provide an adjustable flow rate for discharging the medium.   
     
     
         10 . The method according to  claim 1 , wherein at least two subsets of the plurality of nozzles are configured to provide different materials,
 wherein a first subset is in fluid communication with a first reservoir containing a first material, and   wherein the second subset is in fluid communication with a second reservoir containing a second material.   
     
     
         11 . The method according to  claim 1 , wherein prior to applying the successive recoating layer of the medium, a height distribution of an upper surface of the recoating layer of the medium on the support and/or the already formed part of the object is determined using a measuring device, wherein applying the successive recoating layer is carried out based on the determined height distribution so as to compensate for unflatness and/or non-uniformity of the measured height distribution. 
     
     
         12 . The method according to  claim 1 , wherein each nozzle is provided with an edge wall extending around an opening area. 
     
     
         13 . The method according to  claim 1 , wherein a flow pulse is provided during initial commencement of discharging the continuous stream of medium. 
     
     
         14 . The method according to  claim 1 , wherein a gas is guided through the nozzles at an end of a discharge. 
     
     
         15 . The method of  claim 6  wherein the coverage area pitch is between 0.5 to 1 times a coverage area diameter times a total number of arrays of the plurality of nozzle arrays.